This application claims the priority of German Patent Application DE 196 45 639.8, the disclosure of which is expressly incorporated by reference herein.
The invention relates to wheel for a motor vehicle and a method of making a wheel for a motor vehicle, and more particularly to a wheel having hollow spokes.
A motor vehicle wheel is disclosed in commonly assigned pending U.S. patent application Ser. No. 08/706,266 filed on Sep. 4, 1996, the entire disclosure of which is expressly incorporated by reference herein, which comprises two shell parts, specifically a rim spider and a rim well, which are connected together to form the wheel. The two shell parts are connected with one another, for example by welding, proximate the air openings, proximate the hub, and proximate a rim hump at on exterior ring area of the two shell parts. The shell parts are molded out such that hollow spokes are formed between the air openings, and annuli are formed proximate the hub and proximate the hump.
It is an object of the invention to provide a vehicle wheel consisting of two shells which has an optimal stability and which is relatively simple to manufacture. It is also an object of the invention to provide a method of making such a vehicle wheel.
This and other objects have been achieved according to the present invention by providing a wheel for a motor vehicle comprising a rim spider connected to a rim well, said rim spider and said rim well defining a plurality of hollow spokes, a plurality of air openings between said hollow spokes, and a plurality of bolt receiving devices, wherein the rim spider includes a plurality of reinforcing ribs on an interior surface, said reinforcing ribs being arranged in at least one of an area between adjacent of said air openings and an area between the bolt receiving devices and the air openings.
This and other objects have also been achieved according to the present invention by providing a wheel for a motor vehicle comprising a rim spider connected to a rim well, said rim spider and said rim well defining a plurality of hollow spokes, a plurality of air openings between said hollow spokes, and a plurality of bolt receiving devices, wherein the rim well includes a plurality of reinforcing ribs on an interior surface, said reinforcing ribs being arranged in at least one of an area between adjacent of said air openings and an area between the bolt receiving devices and the air openings.
This and other objects have also been achieved according to the present invention by providing a method of manufacturing a wheel for a motor vehicle comprising: forming a rim spider for connection to a rim well to form a wheel including a plurality of hollow spokes, a plurality of air openings between said hollow spokes, and a plurality of bolt receiving devices, wherein said rim spider is formed to define a plurality of reinforcing ribs on an interior surface of said rim spider in at least one of an area between adjacent of said air openings and an area between the bolt receiving devices and the air openings.
The present invention advantageously optimizes stability of the rim spider and of the rim well, due to the arrangement of ribs on the interior surface of the rim spider and on the interior surface of the rim well, particularly in areas between the air openings and/or in areas of the wheel bolt receiving devices and/or in areas of the hub. In this way, an optimum stability of the whole wheel is achieved.
The reinforcing ribs are arranged in areas of the rim spider and/or of the rim well which are relatively structurally weaker, in order to provide a definite reinforcement in these areas. Such a reinforcement is particularly beneficial in the case of a narrow wall thickness. Furthermore, the type of the reinforcing ribs and their number are also dependent on the material of the rim spider and of the rim well. Thus, for example, in the case of a rim spider or a rim well made of a relatively less strong material, such as a magnesium alloy, several reinforcing ribs are required, while, in the case of a rim spider or a rim well made of a relatively stronger material, such as an aluminum alloy, fewer reinforcing ribs are required.
In connection with the reinforcing ribs on the interior surface of the rim spider, a ring rib is provided which connects the projecting bolt receiving devices, is arranged concentrically to the wheel hub and is peripherally connected with the wheel bolt receiving devices.
At least two mutually crossing webs are provided between the air openings of the rim spider in the hollow spokes, in order to increase stability in the hollow spokes. These webs have a height which corresponds approximately to half the height of the pulled-up edges of the air openings. In particular, the height is selected such that the webs do not abut the opposite covering wall of the rim well.
In addition to the mutually crossing reinforcing ribs, additional reinforcing ribs are provided between the wheel bolt receiving devices and the edges of the air openings. The reinforcing ribs supplement one another on the whole in an advantageous manner such that the area is additionally reinforced starting from the wheel bolt receiving devices and radially into the hollow spokes. Furthermore, a strong connection is formed by way of the ring rib around the wheel hub and between the air openings.
Together, the reinforcing ribs approximately define a closed parallelogram which is adjoined by two triangles formed by mutually crossing sections of the reinforcing ribs.
The rim spider may be made of various materials, such as an aluminum alloy, a magnesium alloy, a titanium alloy or of a ferrous metal. The rim spider can be manufactured by a casting process, for example, in the case of light-metal materials, by an injection molding process or another manufacturing process, such as a forming process or a pressing process.
The rim well and the rim spider can be made of a magnesium alloy. However, both the rim well and the rim spider may be made of an aluminum alloy. It is also possible to manufacture the rim well and the rim spider of different materials, such as an aluminum alloy and a magnesium alloy. Thus, for example, the rim spider can be made of a magnesium alloy and the rim well can be made of an aluminum alloy or the rim spider can be made of an aluminum alloy and the rim well can be made of a magnesium alloy.
According to the stresses occurring on the wheel, the reinforcing ribs are placed locally on the interior side of the rim spider. Thus several longitudinally and/or transversely extending reinforcing ribs may also be arranged in the area of the hollow spokes which can be supplemented by ribs, webs or the like in areas between the air openings and the exterior edge of the rim spider. Mutually supplementing ribs, webs or the like may also be arranged in the direct hub area between the concentric reinforcing rib and the wheel hub, in which case an additional concentric reinforcing rib is also conceivable between the bolt receiving devices and connects these with one another.